I changed mine at 3000 with Motorcraft Semi Synthetic, then again at 6500 with Mobil 1 Full Synthetic. I'll probably change it again at 10,000, then 5,000 mile intervals after that. I'd recommend changing the factory fill at or before the 3,000 mile mark. Just my opinion.
2011 F150 FX4 SuperCrew 157" Ecoboost
Raptor conversion with Fox 3.0's.